1. Field of the Invention
The present invention relates to an inner-rotor motor.
2. Description of the Related Art
In recent years, there has been a demand for small-sized and high-power inner-rotor motors.
In order to increase power of the motor, it is necessary to increase the number of laminated magnetic steel sheets of an armature, or to increase the thickness of a conducting wire.
In a motor described in JP-A 11-220860, a fixing screw 7 is passed through a ring-shaped stator 1 in an axial direction, and this fixing screw 7 is used to fasten cover members 5 and 6 to the ring-shaped stator 1.
Meanwhile, in a motor described in JP-A 2001-136699, a metallic part having a high thermal conductivity, such as a screw 9, a rivet 10, or a burr 11, is passed through a hole 8 to attach a stator core 13 to a base 16. At this time, a raised portion 17 or an insulator 14, which is made of an insulating material, is arranged between the metallic part and a conducting wire 5 to prevent a contact between the metallic part and the conducting wire 5.
An increase in the number of laminated magnetic steel sheets of the armature results in increased power of the motor. Also, an increase in the thickness of the conducting wire allows an increased amount of current to pass therethrough. However, both the increase in the number of laminated magnetic steel sheets of the armature and the increase in the thickness of the conducting wire conflict with a demand for a reduction in the thickness of the motor.